atti delle giornate di coniglicoltura asic 2011 - Fondazione iniziative ...

Atti delle Giornate di Coniglicoltura AsIC 2011 – 8-9 aprile 2011 – Forlì – Italia
tive stages. Therefore, it is suspect that the vaginal environment in precoital rabbits
is comparable to that during diestrus or anestrus in mice, rats, hamsters, and dogs
(noguchi et al., 2003) and nothing is known about interactions of the normal non
pathogen flora with Gnrh analogues.
• Vaginal vascularization. The second layer under epithelium is the lamina propria,
or tunica, made of collagen and elastin, which contains a rich supply of vascular
and lymphatic channels mainly in the urovagina (oh et al., 2003). secretions from
the vaginal wall are transudate in nature and are produced by the engorgement of
the vascular plexus that encompasses the vagina. Vaginal secretions help to protect
the vagina against of infections.
because the extensive vascular connections between the vagina and uterus, a first uterine
pass effect has been hypothesized when hormones are administered vaginally (de
Ziegler et al., 1997). in turn, the rabbit ovary has a dual blood supply: ovarian and uterine
arteries. The ovarian bifurcation of the uterine artery creates utero-branch, which
supplies the tip of the uterine horns, the oviduct and also forms anastomosis with a primary
branch of the ovarian artery. any disturbance in this communication, like a bilateral
uterine ligation, causes significant hypo ovulation by increasing follicular atresia
and impairs hormonal balance (razi et al., 2010). Thus, there is a link between vaginauterus
and ovary by this important vascular junction that could be involved in the systemic
absorption of Gnrh analogues or other substances with direct action in the ovary.
Quintela et al. (2004) observed a serum Lh peak after intravaginal administration of
buserelin, showing a pituitary response to Gnrh absorbed from muscular tissue or
from vaginal mucosa, respectively. These results have been confirmed in recent experiments
(Figure 2; groups mb and Vb; rebollar P.G, data unpublished).
Figure 2 – Plasma LH concentrations of does (mean ± s.e.m; ng/ml) before (0) and after (60’) treatments.
MB: i.m. injection of 1 µg buserelin per doe; VB: buserelin added to extender (10 µg/0.5 ml per doe); Rs: using
a pool of undiluted semen obtained from 8 males (0.5 ml/doe) and i.m. saline; s: inseminated using 0.5
ml of saline and i.m. saline; A: received lumbar anaesthesia and only the empty glass catheter was introduced
in the vagina and i.m. saline (a, b, c: P < 0.05).
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